Nutrition

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NUTRITION

• M.Prasad Naidu
• MSc Medical Biochemistry, Ph.D,.

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Introduction

• Energy expenditure
• 2 types
• Energy Expenditure in doing D2D activities
• EE in doing involuntary works
• Calorific value of foods
• Bomb calorimeter
• Unit of Energy

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Introduction

• Calorific value may be defined as the amount of
  heat energy obtained by burning 1gm of the food
  stuff completely in the presence of O2
• A calorie may be defined as the amount of heat
  required to raise the temp of 1gm of water by 10C
• Average values
• Car 4.1 Fats 9.3 Pro-4.7

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BMR

• The rate of energy production under basal
  conditions per unit time (1hr) and per sq.mt of
  body surface is known as BMR or
• the amount of heat given out by a subject who
  though awake is lying a state of max.physical and
  mental rest under comfortable conditions of temp,
  pressure humidity, 12-18hrs after meal (post
  absorptive state)

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Basal conditions

• Person should awake but at complete rest both
  physical and mental
• Person should be without food for atlease
  12-18hrs i.e., post absorptive state
• Person should be in recumbent /reclining position
  on bed
• Person should remain in normal environmental
  conditions like normal temp, humidity, pressure
  etc

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Determination of BMR

• 1. Open circuit method both O2 consumption and
  CO2 output are measured
• Requires a high degree of tech skill and a
  combussom apparatus
• Less rapid and more accurate
• Tissot method and Douglous method
• 2. Closed circuit method only O2 consumption
• Clinical practice (2-6 min under basal
  conditions)
• Closed circuit system
• Benedict-roth metobolism apparatus

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Factors affecting BMR

• Age children much higher than adults
• 6y?65.5
• 12y?50.4
• 20-30y ?40
• 40-70y ? 38.5 to 35
• Sex women lt males (females 5-17y more)
• Surface Area a BMR ( Cal/Sq.m/hr)
• Climate colder (high) tropical (low)
• State of Nutrition BMR ? malnutrition,
  starvation
• Body Temp BMR ?10 with a rise in 10C
• Barometric pressure rapid fall of O2 ? BMR
• Habits Trained athlets manual workers
• Drugs Caffine, Benzidrine,epinephrine,alcohol ?
  BMR
• Anaesthetics ? BMR
• Hormones thyroid, adrenal medulla, anterior
  pituitary ? BMR
• ! Mg thyroxine ? BMR by about 1000 cal
• Androgens ? 10 ? BMR
• Pregnancy the BMR of pregnant mother after 6
  months of gestation rises

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Clinical aspect

• Pathological variations in BMR
• 1. Fever
• 2. Diseases (Leukaemias 21-80), (Polycythemia
  10-40),(Cardiac failure / hypertension 28-80)
• 3. Endocrine Diseases
• Determination of BMR is mainly used for the
  assesment of thyroid function
• In Hyperthyroidism ?75 or more
• In hypothyroidism ? -40 or more

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Importance of BMR

• As a diagnostic aid
• In the calculation of caloric requirements of an
  individual for prescribing a diet of adequate
  calorific value and planning nutrition for
  individuals or communities and populations at
  large
• To note the effect of foods and drugs on BMR

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THANK YOU